The long-term objective of this research plan is to use the patch clamp technique to study the pathophysiology of retinal glial cells. Knowing more about retinal glial cells is desirable since these cells appear to be involved in a number of vitreoretinal disorders. A specific aim is to use the patch clamp technique to study the physiology, pharmacology and regulation of ionic channels in retinal glial cells from adult rats and from humans undergoing vitrectomies. Preliminary findings indicate that rat retinal glial cells can possess at least two kinds of ionic channels. Experiments also show that it is feasible to detect ionic channels in glial cells obtained from patients. The limited knowledge concerning ionic channels of retinal glial cells may be an important gap in our understanding of the pathophysiology of this class of cells. Ionic channels are likely to play important roles in cellular activities under normal and pathophysiological conditions. At present, there are no patch clamp studies, other than in the Preliminary Studies section of single ionic channels in retinal glial cells from mammals. The identification of ionic channels, a description of their physiology, pharmacology and regulation, may help provide the framework for analyzing the pathophysiology of retinal glial cells at a biophysical level.